"G. Morgan" wrote in message
news
z wrote:

Resistors heat == inefficient

But the resistor will always be there. You are just making a bigger
resistor, the current will drop and the light will dim in a vary
linear way.
The voltage you drop across your resistor will be the same no matter
how big it is. That is not like a rheostat on an incandescent where
you are changing the voltage applied todrop the filament.

The voltage across the resistor *does* change. Also, P=I^2R.

How does the voltage change across a fixed circuit? I think
everyone here is talking about an Xmas tree lighting situation
(now), in a series arrangement.


The circuit is not fixed. The conversation is that you change the resistor
value to change the brightness of the LEDs. There is very little change in
the voltage across the LEDs, but the big change is the voltage drop across
the series resistor as the value of it is changed to change the current that
changes the brightness of the LEDs.